I searched on the internet and there are wonderful web sites where you can learn about trees. From there, I found the information below, which you can read if you click here:
oldest trees
The oldest trees are determined by growth ring counts in cores taken from the edge to the center of the tree or from entire cross-sections. Accurate determination is only possible for trees which produce growth rings, generally those which occur in seasonal climates; trees in uniform non-seasonal tropical climates grow continuously and do not have distinct growth rings. It is also only possible for trees which are solid to the centre of the tree; many very old trees become hollow as the dead heartwood decays away. For some of these species, age estimates have been made on the basis of extrapolating current growth rates, but the results are usually little better than guesswork or wild speculation.
The verified oldest measured ages are (Taken from the Gymnosperm Database):
1. Great Basin Bristlecone Pine Pinus longaeva: 4844 years
2. Alerce Fitzroya cupressoides: 3622 years
3. Giant Sequoia Sequoia sempervirens: 3266 years
4. Huon-pine Lagarostrobos franklinii: 2500 years
5. Rocky Mountains Bristlecone Pine Pinus aristata: 2435 years

Other species suspected of reaching exceptional age include European Yew Taxus baccata (probably over 3000 years) and Western Redcedar Thuja plicata.

The oldest verified age for an angiosperm tree is 2293 years for the Sri Maha Bodhi Sacred Fig (Ficus religiosa) planted in 288 BC at Anuradhapura, Sri Lanka; this is also the oldest human-planted tree with a known planting date.

It depends on the species tree.Some species don't live too long, maybe 40 or 50 years for some palm trees, but some can live up to 5000 years, such as the Bristlecone Pine (Pinus longaeva).

Most tree species live on the order of one to a few hundred years, and so will easily outlive a person, and can also outlive some countries. For example, many of the giant redwoods on the central coast of California were alive when Christopher Columbus discovered the new world, and were alive when the founding fathers rebelled against England, and will still be around in another several hundred years.

Trees can live anywhere from less than 100 years up to more than a few thousand years. It all depends on what type of tree it is. In the United States, the tree with the longest lifespan is the bristle cone pine,which grows in the mountains of Nevada and southern California. A singletree can live up to 5,000 years!